They tried to pose a series of questions through their solicitor to Mr Bradford, who had been in a relationship with their daughter for seven years, but he refused to answer.

Recording a verdict of misadventure coroner Dr David Osborne said: "I am conscious the family would have liked answers to questions about the way in which Mr Bradford sought help. But he is within his rights not to answer on the grounds he could be criminally implicated."

Police said Mr Bradford had told them that he bought the drug at Swansea's Revolution nightspot.

DC Philip Butt said Mr Bradford was questioned in connection with the possession and supply of cocaine but the Crown Prosecution Service decided it was 'not in the public interest' to take the case to court.

The death of Miss Brittain reflects the drug crisis which has led Britain to be named the 'cocaine capital' of Europe. The European Union's drugs agency found that the drug was the new 'stimulant of choice' and was more popular than Ecstasy or amphetamines. It found that one in 20 young Britons had used cocaine in the 12 months up to December 2005 and more than one in ten had tried the drug at some time. Demand for the drug has been fuelled by plunging prices which has left a line of cocaine costing as little as a cup of coffee.

Cocaine tightens up blood vessels, making the heart work harder and raising blood pressure. As little as two 100mg lines (a fraction of an ounce) is enough to cause chest pains.

Regular use puts a massive strain on blood vessels in the heart, causing it to age prematurely and increasing the risk of heart attacks. In 2003 there were 132 deaths directly attributed to cocaine.

A study at St Mary's Hospital in Paddington, West London, found that one in three men under 30 who arrived at its casualty department complaining of chest pains had been using cocaine.

The three-year investigation found that on Friday and Saturday nights, as many as half the young people who turned up for treatcocaine

ment at A & E had cocaine in their system. The results of the study were published last October. Professor John Henry, a toxicologist and professor of accident and emergency medicine, who led the study, said: "It's a healthcare disaster, and it's coming here. We're going to see more addiction, more strokes and heart attacks in young people, and more of the other complications linked to its usage."

The study found that usage was higher in the under-40s - a third of this group tested positive for the drug on weekdays, rising to 50 per cent at the weekend.

In 2004, 8,070 people were convicted or cautioned for possessing or dealing cocaine - up 180 per cent from 2,880 in 1997 when Labour came to power.